<template>
  <!-- 轮播图 -->
  <div id="404">
    <!-- include the svg assets later used in the project -->
    <svg style="display: none">
      <symbol
        id="keyhole"
        xmlns="http://www.w3.org/2000/svg"
        width="100"
        height="100"
        viewBox="0 0 26.458333 26.458334"
      >
        <g transform="translate(0 -270.542)">
          <circle
            cx="13.229"
            cy="279.141"
            r="8.599"
            fill="#f1eedb"
            paint-order="stroke fill markers"
          />
          <path
            d="M10.516 283.271h5.427c1.164 0 1.768.861 2.102 1.802l3.59 10.125c.334.94-.937 1.802-2.102 1.802H6.926c-1.165 0-2.437-.861-2.103-1.802l3.59-10.125c.334-.94.938-1.802 2.103-1.802z"
            fill="#f1eedb"
            paint-order="stroke fill markers"
          />
          <circle
            r="6.06"
            cy="279.141"
            cx="13.229"
            fill="#282b24"
            paint-order="stroke fill markers"
          />
          <path
            d="M11.502 283.76h3.455c.741 0 1.126.733 1.338 1.534l2.286 8.614c.213.8-.597 1.534-1.338 1.534H9.216c-.742 0-1.551-.733-1.339-1.534l2.286-8.614c.212-.8.597-1.534 1.339-1.534z"
            fill="#282b24"
            paint-order="stroke fill markers"
          />
        </g>
      </symbol>
      <symbol
        id="key"
        xmlns="http://www.w3.org/2000/svg"
        width="100"
        height="100"
        viewBox="0 0 26.458333 26.458334"
      >
        <circle
          cx="13.229"
          cy="279.141"
          r="8.599"
          paint-order="stroke fill markers"
          transform="matrix(0 -.76923 .7499 0 -202.882 23.405)"
          fill="#f1eedb"
        />
        <circle
          r="8.599"
          cy="279.141"
          cx="13.229"
          paint-order="stroke fill markers"
          transform="matrix(0 -.5887 .57392 0 -153.756 21.017)"
          fill="#282b24"
        />
        <path
          fill="#f1eedb"
          paint-order="stroke fill markers"
          d="M12.03 12.13h14.428v2.2H12.03z"
        />
        <path
          fill="#f1eedb"
          paint-order="stroke fill markers"
          d="M18.147 12.13h2.895v6.772h-2.895zM22.113 12.13h2.716v5.065h-2.716z"
        />
      </symbol>
      <symbol
        id="ghost"
        xmlns="http://www.w3.org/2000/svg"
        width="100"
        height="100"
        viewBox="0 0 26.458333 26.458334"
      >
        <g transform="translate(0 -270.542)">
          <path
            d="M4.63 279.293c0-4.833 3.85-8.751 8.6-8.751 4.748 0 8.598 3.918 8.598 8.75H13.23zM4.725 279.293h16.914c.052 0 .19.043.19.096l-.095 14.329c0 .026-.011.05-.028.068a.093.093 0 0 1-.067.028c-.881 0-1.235-1.68-2.114-1.616-.995.072-1.12 2.082-2.114 2.154-.88.064-1.233-1.615-2.115-1.615-.881 0-1.233 1.615-2.114 1.615-.881 0-1.233-1.615-2.114-1.615-.882 0-1.236 1.679-2.115 1.615-.994-.072-1.12-2.082-2.114-2.154-.88-.063-1.41 1.077-2.114 1.616-.021.016-.05-.01-.067-.028a.097.097 0 0 1-.028-.068v-14.33c0-.052.042-.095.095-.095z"
            fill="#f1eedb"
            paint-order="stroke fill markers"
          />
          <path
            d="M15.453 281.27a1.987 1.94 0 0 1-.994 1.68 1.987 1.94 0 0 1-1.987 0 1.987 1.94 0 0 1-.994-1.68h1.988z"
            fill="#282b24"
            paint-order="stroke fill markers"
          />
          <g fill="#282b24" transform="matrix(1 0 0 1.0177 .283 -5.653)">
            <ellipse
              cx="10.205"
              cy="278.668"
              rx="1.231"
              ry="1.181"
              paint-order="stroke fill markers"
            />
            <ellipse
              ry="1.181"
              rx="1.231"
              cy="278.668"
              cx="16.159"
              paint-order="stroke fill markers"
            />
            <ellipse
              ry=".331"
              rx=".853"
              cy="280.936"
              cx="10.205"
              opacity=".5"
              paint-order="stroke fill markers"
            />
            <ellipse
              cx="16.159"
              cy="280.936"
              rx=".853"
              ry=".331"
              opacity=".5"
              paint-order="stroke fill markers"
            />
          </g>
          <ellipse
            ry=".614"
            rx="8.082"
            cy="296.386"
            cx="13.229"
            opacity=".1"
            fill="#f1eedb"
            paint-order="stroke fill markers"
          />
        </g>
      </symbol>
    </svg>

    <!-- include in a container a heading, paragraph and svg for the keyhole -->
    <div class="container">
      <h1>404</h1>
      <p>您访问的界面不存在哦！</p>
      <svg class="keyhole">
        <use href="#keyhole" />
      </svg>
    </div>

    <!-- outside of the container, to have them absolute positioned in relation to the body, include an svg for the key and one for the ghost -->
    <svg class="key">
      <use href="#key" />
    </svg>

    <!--
  the div and svg behave differently when translating the element through the transform property, giving a nice distance between the text (included with a pseudo element on the div) and the svg
-->
    <div class="ghost">
      <svg class="ghost">
        <use href="#ghost" />
      </svg>
    </div>
  </div>
</template>
    
    <script>
export default {
  mounted() {},

  name: "403",
};
</script>
    
    
    
<style lang="less" scoped>
@import url("https://fonts.googleapis.com/css?family=Open+Sans|Nova+Mono");
:root {
  --font-header: "Nova Mono", monospace;
  --font-text: "Open Sans", sans-serif;
  --color-theme: #f1eedb;
  --color-bg: #282b24;

  --animation-sentence: "You know you're supposed to leave, right?";
  --animation-duration: 40s;
}
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
body {
  width: 100%;
  font-family: var(--font-text);
  color: var(--color-theme);
  background: var(--color-bg);
  overflow: hidden;
}
.container {
  text-align: center;
  margin: 1rem 0.5rem 0;
}
.container h1 {
  font-family: var(--font-header);
  font-size: calc(4rem + 2vw);
  text-transform: uppercase;
}
.container p {
  text-transform: uppercase;
  letter-spacing: 0.2rem;
  font-size: 2rem;
  margin: 1.5rem 0 3rem;
}
svg.keyhole {
  height: 82px;
  width: 82px;
  opacity: 0;
  visibility: hidden;
  /* define an animation for the keyhole, to introduce it
  paused by default, run with a timeout in JavaScript
  */
  animation: showKey 0.5s 0.5s paused ease-out forwards;
}
svg.key {
  height: 164px;
  width: 164px;
  position: absolute;
  opacity: 0;
  visibility: hidden;
  /* define an animation for the keyhole, to introduce it
  paused by default, run with a timeout in JavaScript
  */
  animation: showKey 0.5s 0.5s paused ease-out forwards;
}
.ghost {
  /* border: 1px solid tomato; */
  position: absolute;
  bottom: 5px;
  left: calc(50% - 100px);
  width: 200px;
  height: 200px;
  /* have the ghost move to the right and to the left of the screen, turning to its central position and repeating the animation twice */
  animation: hoverGhost calc(var(--animation-duration) / 2) ease-in-out 2;
}
/* introduce text through a pseudo element, connected to the animated div */
.ghost:before {
  content: var(--animation-sentence);
  color: var(--color-theme);
  border-radius: 50%;
  position: absolute;
  bottom: 100%;
  text-align: center;
  line-height: 2;
  padding: 1rem;
  visibility: hidden;
  opacity: 0;
  /* have each string of text introduced as the ghost returns from the right edge of the screen, and for the length of time it takes to cover the central portion (a fourth, which becomes an eight as the animation length is half the total duration) */
  /* the delay for an hypothetical duration of 40s is 7.5s for the first, 27.5s for the second and finally 40s for the last
  in fractions and with a bit of math it boils down to 3/16, 27/40 and 1
  // ! remember to include a slight delay in the animation of the key and keyhole
  */
  animation: showText calc(var(--animation-duration) / 8)
      calc(var(--animation-duration) * 3 / 16) ease-out forwards,
    showNewText calc(var(--animation-duration) / 8)
      calc(var(--animation-duration) * 27 / 40) ease-out forwards,
    showFinalText calc(var(--animation-duration) / 8) var(--animation-duration)
      ease-out forwards;
}

/* define the keyframe animations
- hoverghost to have the ghost move right, left and then back to its default position
- showKey to introduce into view the key (and keyhole) svg
- showText, showNewText, showFinalText to show the different strings (the implementation is quite quirky and primed for optimization)
 */
@keyframes hoverGhost {
  25% {
    transform: translateX(20vw);
  }
  75% {
    transform: translateX(-20vw);
  }
}

@keyframes showKey {
  to {
    opacity: 1;
    visibility: visible;
  }
}

/* alter the text changing the value of the custom property, weary of changing its value when the pseudo element is hidden and changing its value in the last keyframe (as the animation gives this value as per the "forwards" value of the fill-mode property)  */
@keyframes showText {
  2% {
    opacity: 1;
    visibility: visible;
  }
  98% {
    opacity: 1;
    visibility: visible;
  }
  99% {
    --animation-sentence: "You know you're supposed to leave, right?";
    opacity: 0;
    visibility: hidden;
  }
  100% {
    --animation-sentence: "So much to do, so little time...";
  }
}
@keyframes showNewText {
  2% {
    --animation-sentence: "So much to do, so little time...";
    opacity: 1;
    visibility: visible;
  }
  98% {
    opacity: 1;
    visibility: visible;
  }
  99% {
    --animation-sentence: "So much to do, so little time...";
    opacity: 0;
    visibility: hidden;
  }
  100% {
    --animation-sentence: "Okay, you seem to care about this. Here's a key just for you";
  }
}
@keyframes showFinalText {
  2% {
    opacity: 1;
    visibility: visible;
  }
  98% {
    opacity: 1;
    visibility: visible;
  }
  100% {
    opacity: 0;
    visibility: hidden;
  }
}
</style>
    